The latest version of the Internet Protocol (IP), IPv6, is increasingly being used to replace IPv4 in networks. As more and more networks are enabled with IPv6, it is likely that IPv4 and IPv6 may co-exist on some nodes and not on other nodes, for years to come. In addition, it is also possible that IPv4-only and IPv6-only networks/clouds may be connected by dual stack border nodes (e.g., devices that support both protocols), for many years.
With the dual support of IPv4 and IPv6 in networks that use an mLDP-enabled core, certain tree redundancies may occur. For example, a set of leaf nodes/devices may build a multipoint label switched path (MP-LSP) towards the IPv6 address of the root node while another set of leaf nodes/devices may build an MP-LSP towards the IPv4 address of the same root node. Depending on the topology of the network, this may lead to certain intermediary nodes/devices treating overlapping IPv4 and IPv6 trees centered at the same root separately.